October 30, 2012

In Research

Exposure to snot-nosed kids ups severity of cold infections

Exposure to school-age children raises the odds that a person with lung disease who catches a cold will actually suffer symptoms like a runny nose, sore throat, and cough, according to a study published in the Journal of Clinical Virology.

That finding, the result of a study that drew upon a databank of 1,000 samples of sputum and nasal secretions from people with chronic obstructive pulmonary disease or COPD, comes as a surprise, says Ann Falsey, professor of medicine at the Medical Center at the and an infectious disease expert at Rochester General Hospital. Falsey is senior author of the study, which was led by first author Anurag Gandhi, an infectious disease fellow at the Medical Center.

“Before we conducted this study, I would have expected other factors, perhaps the severity of underlying disease—the state of the patient’s general health—to indicate who would actually suffer symptoms from their colds,” says Falsey. “Instead, contact with school-age children is the only risk factor we found, and it increases both the risk of infection and also the risk of suffering symptoms once you’ve caught a cold.”

Many studies, including this one, have found that being around school-age children increases the risk of infection, but the new findings go one step further. Of people who come down with colds, the course of the infection is much more likely to be worse in people exposed to children.

In everyday life, many people have no symptoms and don’t even realize it when they catch a cold. It comes as no surprise that Gandhi and Falsey found that more than one-third of people infected with a rhinovirus, the bug that causes most colds, had no symptoms.

Further analysis of the data showed that of those people who were infected, people whose infection turned into real-life symptoms—congestion, runny nose, sore throat, hoarseness and so on—were about twice as likely to have contact with school-age children as people whose infections did not become symptomatic. Read more at www.urmc.rochester.edu/news.

Choline may influence gene expression from infancy to adulthood

Just as women are advised to get plenty of folic acid around the time of conception and throughout early pregnancy, new research suggests another very similar nutrient may one day deserve a spot on the obstetrician’s list of recommendations.

Consuming greater amounts of choline—a nutrient found in eggs and meat—during pregnancy may lower an infant’s vulnerability to stress-related illnesses, such as mental health disturbances, and chronic conditions, like hypertension, later in life.

In an early study in the FASEB Journal, nutrition scientists and obstetricians at the Medical Center and Cornell University found that higher-than-normal amounts of choline in the diet during pregnancy changed epigenetic markers—modifications on our DNA that tell our genes to switch on or off, to go gangbusters or keep a low profile—in the fetus. While epigenetic markers don’t change genes, they make a permanent imprint by dictating their fate: if a gene is not expressed—turned on—it’s as if it didn’t exist.

Researchers discovered that the affected markers were those that regulated the hypothalamic-pituitary-adrenal, or HPA axis, which controls virtually all hormone activity in the body, including the production of the hormone cortisol that reflects our response to stress and regulates our metabolism, among other things.

More choline in the mother’s diet led to a more stable HPA axis and consequently less cortisol in the fetus. As with many aspects of our health, stability is a very good thing: Past research has shown that early exposure to high levels of cortisol, often a result of a mother’s anxiety or depression, can increase a baby’s lifelong risk of stress-related and metabolic disorders.

“The study is important because it shows that a relatively simple nutrient can have significant effects in prenatal life, and that these effects likely continue to have a long-lasting influence on adult life,” says Eva Pressman, study author and director of the high-risk pregnancy program at the Medical Center. “While our results won’t change practice at this point, the idea that maternal choline intake could essentially change fetal genetic expression into adulthood is quite novel.” Read more at www.urmc.rochester.edu/news.

Language shaped by brain’s desire for clarity and ease

Using an artificial language in a carefully controlled laboratory experiment, a team from Rochester and Georgetown University has found that many changes to language are simply the brain’s way of ensuring that communication is as precise and concise as possible.

“Our research shows that humans choose to reshape language when the structure is either overly redundant or confusing,” says T. Florian Jaeger, the Wilmot Assistant Professor of the Sciences at Rochester and coauthor of a study published in the Proceedings of the National Academy of Sciences. “This study suggests that we prefer languages that on average convey information efficiently, striking a balance between effort and clarity.”

The brain’s tendency toward efficient communication may also be an underlying reason that many human languages are structurally similar, says lead author Maryia Fedzechkina, a doctoral candidate at Rochester. Over and over, linguists have identified nearly identical grammatical conventions in seemingly unrelated languages scattered throughout the globe. For decades, linguists have debated the meaning of such similarities: are recurrent structures artifacts of distant common origins, are they simply random accidents, or do they reflect fundamental aspects of human cognition?

This study supports the latter, says coauthor Elissa L. Newport, professor of neurology and director of the Center for Brain Plasticity and Recovery at Georgetown, and the former George Eastman Professor of Brain and Cognitive Sciences at Rochester. “The bias language learners have toward efficiency and clarity acts as a filter as languages are transmitted from one generation of learners to another,” she says. Alterations to language are introduced through many avenues, including the influence of other languages and changes in accents or pronunciation. “But this research finds that learners shift the language in ways that make it better—easier to use and more suitable for communication,” says Newport. That process also leads to the recurrent patterns across languages. Read more at www.rochester.edu/news.

Motion detector’ shrinks to microscale

A new class of microsensors could be used in consumer electronics, as well as oil and gas exploration and biomedical situations in which more traditional sensors can’t operate.

Imagine navigating through a grocery store with your cell phone. As you turn down the bread aisle, ads and coupons for hot dog buns and English muffins pop up on your screen. The electronics industry would like to make such personal navigators a reality, but, to do so, they need the next generation of microsensors.

Researchers at the California Institute of Technology (Caltech) and Rochester have developed an ultrasensitive accelerometer—a type of motion detector—that brings this new class of microsensors a step closer to reality.

The device and its capabilities are described in an advance online publication of Nature Photonics.

Rather than using an electrical circuit to gauge movements, their accelerometer uses laser light. And despite the device’s tiny size, it is an extremely sensitive probe of motion. Thanks to its low mass, it can also operate at a large range of frequencies, meaning that it is sensitive to motions that occur in tens of microseconds, thousands of times faster than the motions that the most sensitive sensors used today can detect.